[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Challenges of adding octal and hexadecimal escape sequences in strin

From: Jose E. Marchesi
Subject: Re: Challenges of adding octal and hexadecimal escape sequences in strings
Date: Sat, 31 Oct 2020 13:36:40 +0100
User-agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux)

> Hi, Jose!
> On Fri, Oct 30, 2020 at 05:51:44PM +0100, Jose E. Marchesi wrote:
>> I don't think that is the desired behavior.  If we define Poke strings
>> as NULL-terminated, it is obvious they are not to contain any NULL
>> byte.  Now, we can achieve that by two ways:
>> a) By doing what we do now, i.e to ignore any part of the string after a
>>    NULL character, in case one is inserted, or
>> b) To emit an error whenever a 0 byte is attempted to be stored in a
>>    string value.
>> Supposing we wanted to switch to b), at the moment the only ways to
>> create a string value in Poke are:
>> b1) Using a string literal, and
>> b2) using a cast from uint<8> to string
>> The first case is easy to implement: just emit a compile-time error if a
>> string literal contains a null character.
>> For the second case we have two choices: either to raise an exception
>> when `8UB as string' is executed, or to keep the current behavior of
>> generating an empty string "", but the latter would be an exception to
>> the rule.
>> That's why I prefer a) to b): it is more orthogonal, and can be
>> explained by a single rule without needing any exceptions to the rule.
>> Also, it comes handy to shorten strings :D
> What about a third way:
> c) Keep Poke strings as NULL-terminated. Treat using of NULL character in 
> string
>    literals as compilation error.
> The user cannot access data beyond the first NULL character, and having bytes
> beyond that character doesn't make any sense.

Isn't that a subset of b) above?

reply via email to

[Prev in Thread] Current Thread [Next in Thread]